Much of the clinical technology available for the identification of pancreatic cancer is based upon antigen recognition by a variety of monoclonal antibodies. Presently, a major difficulty hindering many of the monoclonal antibody assays is the presence of these antigens in normal pancreas, and in benign pancreatic disease. It is imperative, therefore, to find additional specific markers that would facilitate accurate and early diagnosis of this too-often terminal disease. The Laboratory of Molecular Oncology has developed an efficient, differential cDNA subtractive hybridization procedure, in which low abundance mRNA species that are differentially expressed can be identified and isolated. This procedure is not dependent upon any a priori knowledge of the gene, gene rearrangements, or the gene products. We have successfully employed this technique to isolate tumor-specific and normal-specific cDNA clones from colon carcinomas and normal cDNA libraries, respectively. Our initial studies have resulted in the isolation of over 1200 unique cDNAs from the diploid, near-normal, and highly-metastatic human pancreatic cell lines obtained from the American Type Culture Collection (ATCC) (HS680.PAN and CAPAN-1, respectively). These cellular probes have yielded more than 300 differentially-transcribed gene products, which have the potential to distinguish genes expressed in pancreatic cancers from those expressed in the normal pancreas. A number of distinctive clones have been identified that are known to be growth factors (LIF), cell growth inhibitors (PAI), or structural proteins (cytokeratins); another 20 gene products are unique and not found listed in any gene banks, and are up-regulated in pancreatic cancer cells relative to normal pancreatic tissue being used to screen and molecularly categorize malignant pancreatic tissue. These are being used to screen and molecularly categorize malignant pancreatic tissue. cDNA probes will be used for in situ and confocal laser scanning microscope (CLSM) studies. State-of-the-art techniques of this type will be employed to define a variety of new molecular probes that can afford increased sensitivity for detection of early pancreatic neoplasia.